<?php
        class SF_AutoCoupon_Model_Promoteevents
        {
            
            public function toOptionArray()
            {
                $result = array();
               $events =  Mage::getModel('promoteevents/events')->getCollection()->getData();
               foreach ($events as $k=>$v){
                   $result[$k]['value'] = $v['event_code'];
                   $result[$k]['label'] = $v['event_title'];
               }
               return $result;
            }
        }